Oil-pressure gauge...not a gauge??

K

Kit Sullivan

Registered User
What is this about the Oil gauges on all SCs not being a real gauge? Why would Ford do that?
I belive the shop manual for 1990 indicates otherwise. It makes mention of three coils of varying lengths on the back of the gauge for a variable reading depending on voltage recived from the sender.
Am I missing something here? If Ford put a 'dummy' gauge in these cars just to fool the public, that is a real crappy way to promote it's 'premium' performance car, don't you think?
 
Kit Sullivan said:
What is this about the Oil gauges on all SCs not being a real gauge? Why would Ford do that?
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Because the kind of person who bought an SC when they first came out didn't want to see an oil pressure gauge fluctuating. It made them nervous and they would bring the cars in for service. It's normal for the oil pressure on an SC to fluctuate a lot. It was done to give the customers piece of mind and to get the SC out of warranty without the dealer having to replace bearings.

See if an SC has very tight bearing clearances it will maintain steady oil pressure from idle on up. But if an SC has looser bearing clearances (but still well within the normal range) pressure can fluctuate from as low as 30psi at idle to 75psi at cruise. To know this would bother some people.

But ya, stupid idea.
 
John Shelton said:
Excuse me, but I take exception to that stereotyping. :p
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LOL! Sorry 'bout that. I meant to say the kind of person Ford *expected* to purchase a new SC ......"

Ok, I'll just stop now because if my foot ends up any further down my throat I'll be tying my shoelaces behind my back......:eek:
 
What about the claim in the shop manual that it is a variable gauge? That would seem to contradict the 'not a gauge' statement.
Even if there is no calibrated number scale on the face of the gauge, just knowing vaugely how high or low the pressure is during operation is still much better than a light.
I beleive I will definately convert mine to a true variable-display gauge...what would be the real point of having a gauge otherwise?
 
XR7 Dave said:
LOL! Sorry 'bout that. I meant to say the kind of person Ford *expected* to purchase a new SC ......"

Ok, I'll just stop now because if my foot ends up any further down my throat I'll be tying my shoelaces behind my back......:eek:
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Yeah...I'm that kind of person who doesn't want to know. I still have all stock gauges in my 91.

Ignorance is bliss.

David
 
Kit Sullivan said:
What about the claim in the shop manual that it is a variable gauge? That would seem to contradict the 'not a gauge' statement.
Even if there is no calibrated number scale on the face of the gauge, just knowing vaugely how high or low the pressure is during operation is still much better than a light.
I beleive I will definately convert mine to a true variable-display gauge...what would be the real point of having a gauge otherwise?
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I've done it to both my SC and my LX.... just getting an idea where things are at inside the motor before its too late gives me a warm fuzzy feeling.

I used the same sender unit in both cars, and the LX (3.8 24000km on rebuild)reads higher around the M than the SC at cruise (190000km no rebuild) which sits around the O.

Both cars are running 10w30, the LX on dyno oil and the SC on mobil1 synth.
 
What about the claim in the shop manual that it is a variable gauge? That would seem to contradict the 'not a gauge' statement.
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The gauge IS an analog meter and will display different readings with changing current flow.

Dave is dead-on with his explanation... people were bringing cars back when they thought the oil pressure was low (and not just SCs either). Their "fix", if you can call it that, was to install a pressure-sensitive switch in place of the analog pressure sensor. That's why the gauge is still an analog type.
 
I totally dissagree with the idea of converting the sensor to provide variable information. You will not gain useful information from it and it will provide you with an even more false sense of security that you have now. Just because you see the gauge move doesn't mean that it's movements are providing useful information.

A drop of 10psi off your normal operating pressure signifies extreme distress and imminent engine failure. This will not show up reliably on the stock gauge even with the conversion. Don't trust it! You should either be like David Neibert and not worry about what your oil pressure values are, or get a real gauge and learn to read what it says and interpret what it means.

Don't say I didn't warn you.
 
Well, mine moves a bit at times, so that's just Voltage fluctuations? Ford is dumb. Now, where can I go about getting a guage pod and a nice oil pressure guage?
 
XR7 Dave said:
I totally dissagree with the idea of converting the sensor to provide variable information. You will not gain useful information from it and it will provide you with an even more false sense of security that you have now. Just because you see the gauge move doesn't mean that it's movements are providing useful information.

A drop of 10psi off your normal operating pressure signifies extreme distress and imminent engine failure. This will not show up reliably on the stock gauge even with the conversion. Don't trust it! You should either be like David Neibert and not worry about what your oil pressure values are, or get a real gauge and learn to read what it says and interpret what it means.

Don't say I didn't warn you.
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I'm not saying I have total trust in it.... I AM saying that when that sucker drops below the N I start biting my nails..... and you ain't gonna get that with the default idiot option, cause when it drops, its too late anyway.

I've had it once drop below the N for a second in the SC when I was going hard around a corner and I immediately shut the motor off, despite the fact the gauge came right back to O.
 
fturner said:
I'm not saying I have total trust in it.... I AM saying that when that sucker drops below the N I start biting my nails..... and you ain't gonna get that with the default idiot option, cause when it drops, its too late anyway.

I've had it once drop below the N for a second in the SC when I was going hard around a corner and I immediately shut the motor off, despite the fact the gauge came right back to O.
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Understood.

Now ask Sean Matteson how much warning his modified gauge gave him of the impending doom of his motor. :eek:

You've got the right idea, just the wrong tool for the job.
 
fturner said:
I'm not saying I have total trust in it.... I AM saying that when that sucker drops below the N I start biting my nails..... and you ain't gonna get that with the default idiot option, cause when it drops, its too late anyway.

I've had it once drop below the N for a second in the SC when I was going hard around a corner and I immediately shut the motor off, despite the fact the gauge came right back to O.
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Hell, I got nervous when I changed from summer oil to winter oil and the idle pressure dropped from 80 to 70!! :eek: Having the stock guage in that car would drive me nuts.

Ira
 
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This is my take on it. I'm sure everyone has their own opinion, and that's fine too :)

Worst solution: stock gauge and stock sender (yields only 2 positions: full left or middle). This is basically like an on/off light, but it's presented by a gauge.

Okay solution: modify sender so that gauge is proportional to oil pressure. Only downfall is that there are no psi markings on the gauge itself. This is currently what I'm running in my car and it is a LOT better than the stock setup. If you've read oil pressure gauges before, then eventually the numbers don't matter anyway, you get a "feel" for what is right/wrong.

Best solution: aftermarket accurate gauge and sender
 
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